Both the blocking voltage as well as the sweep voltage (blocking voltage after which the thyristor switches into the conductive condition) of a thyristor exhibit a pronounced temperature behavior. Thus, the blocking and the sweep voltage initially continuously increase with the temperature, reach a maximum, in order to ultimately drop to comparatively low values. Whereas the influence of the positive temperature coefficient of the avalanche coefficients characterizing the electron multiplication by impact ionization predominates at low and moderate temperatures, the drop of the blocking and sweep voltage at higher temperatures T.gtoreq.100.degree. C. can be attributed to the dominance of the positive temperature coefficient of the transistor current gain .alpha..sub.pnp as a result of the greatly increasing blocking current. The temperature dependency of the blocking and sweep voltage has an especially disturbing influence in highly inhibiting thyristors that exhibit a protection against overhead ignition integrated in the semiconductor body. Given these thyristors, the blocking and the sweep voltage can change by up to 15% in the relevant temperature range (5.degree. C.-120.degree. C.). For example, the sweep voltage thus rises from U.sub.BO =8.0 kV to values U.sub.BO.apprxeq.9.2 kV when the thyristor heats from T=23.degree. C. to T=90.degree. C. during operation.
The user must take this effect into account with a more complicated wiring of the thyristor. The manufacturer of the component, by contrast, is compelled to keep the scatter of the parameters (basic doping of the Si substrate, dopant profiles, contour of the edge termination, etc.) that influence the blocking or respectively, sweep voltage extremely low. The product becomes substantially more expensive due to the high technological outlay given simultaneously reduced yield that accompanies this.